f-string语法错误？

我用VSCODE运行下代码提供语法错误改怎么修改？
import xlwings as xw
app=xw.app(visible=true,add_book=false)
for i in range(1,21):
workbook=app.books.add()
workbook.save(f"c:\\Users\\Administrator\\Desktop\\xw{i}.xlsx")

workbook.close()
app.quit()